Chemical Mechanical Polishing, or Chemical Mechanical Planarization, (CMP) is used in the manufacture of advanced semiconductor devices which contain copper interconnects. Copper has become the material of choice for the interconnects in advanced semiconductor devices due to its low resistance and ease of processing. Device fabrication with copper requires electrochemical deposition and CMP. Since the polished copper surface generated during CMP is considered to be one of the most important factors which determine the performance of the interconnects, post-CMP cleaners must efficiently remove any residues that may be generated by the polishing process. Thus, CMP slurries and post-CMP cleaners frequently include one or more corrosion inhibitors which are selected to form a temporary protective layer on the copper interconnect surface. However, if an organic film should remain on the copper interconnect surface after the cleaning process, the presence of such a film can interfere with subsequent steps, e.g., chemical vapor deposition (CVD), and with the ultimate performance of the copper interconnect. In post CMP cleaning processes, therefore, it is an important objective to have low organic residue(s) remaining on the copper surfaces and low corrosion of the copper interconnect. A conventional corrosion inhibitor, such as, for example, benzotriazole (BTA) can suppress corrosion of copper in a semiconductor device. However, BTA, and corrosion inhibitors of that type, will typically leave a hydrophobic layer on the copper surfaces which, in turn, contributes to formation of undesirable high organic residues. In addition, a conventional amine, such as, for example, 2-aminoethanol, can remove organic residues from the copper surface, but conventional amines have also been observed to etch the copper interconnect surface thereby creating corrosion defects. A slurry comprising a solution of an abrasive and an active chemistry yields a unique and even synergistic combination of physical and chemical action that can preferentially remove complex layers of metals and other undesirable materials from a wafer surface in preparation for subsequent patterning, etching and thin-film processing.
Accordingly, there remains a need for a cleaning composition capable of providing post-CMP cleaning of a semiconductor device which contains copper interconnects and that not only removes organic residue(s), but also minimizes copper corrosion.